Single port gas burner and removable flame deflector



y 1956 1.. E. HERSHEY 2,754,395

SINGLE PORT GAS BURNER AND REMOVABLE FLAME DEFLECTOR Filed Jan. 2, 19522 Sheets-Sheet l I [Even b7 LAW? Lowell E Herskgy July 17, 1956 E.HERSHEY SINGLE PORT GAS BURNER AND REMOVABLE FLAME DEFLECTOR Filed Jan.2, 1952 2 Sheets-Sheet 2 Lowell z. me s/L United States Patent SINGLEPORT GAS BURNER AND REMOVABLE FLANIE DEFLECTOR Lowell E. Hershey,Kalamazoo, Mich assignor to Borg- Warner Corporation, Chicago, Ill., acorporation of Illinois Application January 2, 1952, Serial No. 264,538

1 Claim. (Cl. 158-113) This invention relates in generalito' gas burnersfor furnaces and other types of heating apparatus; and is particularlyconcerned with gas burner nozzles or burner heads for employment in themixture and burning of combustible gases and air as" required forexample, in equipment originally designed for gas burning or in burnerassemblies of the gas conversion type for conventional domestic heatingfurnaces originally designed for other types of fuel.

The expression burner nozzles or burner heads must be understood to meanany device, or that portion of a burner assembly, from which. isdischarged a jet of burn ing fuel.

In fuel burning devices, numerous attempts have been made to provide agas burner nozzle or burnerhead' which would meet the rigid requirementsof burner operation in practical use. Of these numerous attempts, therehave been designed many types of burner heads, some of which have beenprovided with a plurality of additional nozzles so that jets of aircould be directed either radially or circumferentially into a stream ofprimary air and gas mixture, others of which have been provided with amultiplicity of apertures or ports so that the primary stream of air andgas is broken into a plurality of streams, thus effectively producing aplurality of flames, and still other attempts have been made to combinethe two above attempted designs by employing both jets of secondary airand a plurality of ports in order to obtain an acceptable usable burnerhead. However, these numerous attempts' have not been met with wideacceptance and approval because several undesirable featu'res ensue.Some of these undesirable features have been high cost of manufacture,extreme ciriticalnessin the adjustment and high cost of operation.

Accordingly, it is a general object of this invention to provide a gasburner head of the single port type which is highly efficient and betteradapted to meet the rigid requirements of burner operation undervarying, gas loads and gas properties.

Another object and accomplishment of my invention is to provide a newand improved means in a burner of this type whereby secondary air ismixed with the flow of primary gas and air in such a manner as toimprove the combustion of the gaseous fuel.

Another goal of my invention. is to provide in burners of this type aburner head of simplified and improved construction in which the use ofadditional jets or other port means for conducing secondary air into thestream of gas and primary air are not necessary.

Another object of my invention is to provide in. burner systems of thistype an improved burner head which cooperates with the mixture of gasand primary air in such a manner as to suitably improve the burning.thereof.

Still another object of my invention. is' to provide in a burnerassembly of this type a new and improved burner head which cooperateswith the mixture of gas:- and: primary air to produce the combustionwhich is not subject to critical adjustment, thereby effectivelyimproving: the burning and operation thereof.

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A still further object of my invention is to provide in a burnerassembly of this type a burner head which will cooperate with themixture of gas: and primary air to produce combustion wherein the rateof flame propagation at the periphery of the air-gas. mixture is equalto the velocity of the primary gas and air mixture at that point so thatthe flame is kept within the port of the burner head thus preventingwhat is commonly known as blow-01f or lifting.

Still another object of my invention is to provide a burner of the typeabove stated which is well adapted to be manufactured at low cost andyet give a maximum of satisfactory service whilein use.

Another object of my invention is to provide in a burner assembly ofthis type a new and improved means for supporting a deflecting plate andarranged" to cooperate with the burner head contemplated by this.invention.

Another goal of the present invention is to provide a burner head of thesingle port type by correlating and especially designingv the variouselements thereof to effect advantageous cooperation between the variouselements as will best serve the purpose of providing. an effectivesystem for the burning of fuel in any gas burning device.

It is still another purpose of this invention to provide a new andimproved burner head of the single port type to be used in any gasburning device which isv adapted to be economically manufactured andwhich is designed to permit manufacture and assembly thereof inaccordance with present day large scale mass production manufacturingmethods of construction and assembly.

My invention seeks as its further object to provide a burner head of thesingle port type particularly characterized by a design arrangement tosatisfactorily perform the functions required of it and adapted to beused in, either equipment originally designed for gas burning, or in aconversion unit and which will successfully combine the factors ofstructural simplicity and durability, andv yet be economical tomanufacture.

Additional objects, features and advantages of the inventiondisclosedherein will be apparent to persons skilled in the art after theoperation and construction thereof are understood from the withindescription.

It is preferred to accomplish the various objects of this invention andto practice the same in substantially the same manner as hereinaftermore fully described, and as more particularly pointed out in theappended claim.

in general, my invention can be described as a new and improved burnerhead which is arranged for full cooperation with the primary mixture of.gas and air and whereby a portion of secondary air, because of thiscooperation, is caused to be intermixed with the outer periphery orlayer of the stream or flow of the primary mixture so that the flame isretained within the burner head. This latter is accomplished byjudiciously and advantageously positioning a ring within the innerperiphery of the burner head in such a manner that secondary air iscaused to travel downwardly into the burner head as far as the ring andsimultaneously be intermixed with the outer layer of the primary gas andair mixture.

Embodiments of the invention are illustrated in the accompanyingdrawings which form a part. hereof and wherein:

Fig. l is a; side elevation view of a burner assembly embodying myinvention with an accompanying diagrammatic illustration. of therelative position of the combustion zone and flow or travel of the gasand air within a furnace;

Pig. 2 is a side elevation view partially broken away of the burner headshowing the details of the means of supporting a deflecting plate. inthe burner assembly depicted in Fig. l. and: with accompanyingdiagrammatic illustration. of. the How of: the primary gas and airmixture as well as the flow of secondary air to aid in combustion;

Fig. 3 is an end view of the burner head looking in the directionindicated by the arrows of line 3-3 in the burner assembly of'Fig. 2 andshowing the detailed construction of its deflecting plate support means;

Fig. 4 illustrates a gas burner head of the type contemplated by thisinvention and disclosed with respect to Figs. 1 to 3 but showing adifferent type of burner assembly with which the burner head of thepresent invention may be employed; and

Fig. 5 is a side elevation of the burner assembly looking in thedirection of the arrows of line 55 of Fig. 4, and partially in section,showing the construction of its deflecting plate and support means indetail.

The drawings are to be understood to be more or less of a schematiccharacter for the purpose of illustrating or disclosing a typical orpreferred form of the improvements contemplated and in the drawings likereference characters identify the same part in the several views.

In the exemplary embodiment shown in Figs. 1 to 3, the burner head of asingle port type with which my invention is primarily concerned isindicated in its entirety by reference numeral 40 and is shown in Figs.1 and 2 as a portion of a tubular member or duct 30 having arms 31 and32, generally at right angles to each other. When the burner assembly ofthis type is installed in its operative position similar to that shownin Fig. 1, the arm 31 is in a vertically disposed position and arm 32,which is extended laterally, is provided with a tube 33 of a venturishape into which fuel comprising a mixture of gas and primary air isreceived for delivery and discharge out the discharge end of the duct30. The flared end 34 of the venturi shaped tube may be operativelydisposed within a casing, designated in its entirety by numeral 35,which would enclose or contain the necessary mechanism (not shown) forcontrolling the supply of and for ejecting gas and air into the venturishaped tube to travel therethrough and be mixed for discharge at the endof the duct 30. The larger or flared end 34 of the tube 33 may betelescopically arranged with reference to the arm 32 of the duct 35) soas to permit adjustment of the gas receiving end of the venturi shapedtube with relation to the discharge end of the arm 31 so that burners ofthis type can readily be installed in different types and sizes offurnaces and heaters, or with the fuel supply connections arranged atdifferent distances from the discharge end of the burner. However, itmust be understood that the burner head 40 is equally adaptable for usein a burner assembly wherein the arm 31 is fixedly arranged with respectto the receiving end of the venturi shaped tube.

As is customary with gas burners, the operation of the fuel supply andcontrol means therefor are subject to control by a safety pilot assemblyindicated in its entirety reference numeral 36 shown mounted near thedischarge port of the duct 30 by a mounting bracket 37. The controlconnections between the pilot assembly and the fuel supply and controlmeans therefor have been omitted in the interest of simplification ofdisclosure.

When the burner is employed in a furnace or heater it is usuallydesirable that the flame thereof be deflected outwardly into substantialcontact with the walls of the combustion chamber (not shown) and whensuch deflecting is desired, a flame deflecting device or plate 38 isemployed and which will be located beyond the discharge end of the duct39 or burner head 40. This deflecting device is supported in theposition shown in Fig. l and in the construction illustrated by asupporting rod 39 mounted coaxially within the duct 30 or burner head 46in a manner that will be explained in detail in relation to thedescription of the burner head.

Referring now to that portion of the burner assembly with which thisinvention is primarily concerned, namely, the burner head 40 which is anend portion of the arm 31 of the duct or tubular member 30, and shown indetail in Fig. 2. It is to be understood that this burner head with itsassociated elements could be made of a separate piece of tubing andsuitably connected with the arm 31 of the tubular duct. It can be seenthat the head may be provided on its outer end with a flared portion 41to expedite manufacturing processes. On the inner surface of the burnerhead there is a ring 42 secured and supported therein by any suitablemeans such as dimples or protuberances 43 and which may be provided witha split, as shown, at 42a to facilitate its insertion or removaltherefrom when desired. To permit the coaxial supporting rod 39 for theflame deflecting plate 38 to be supported on the burner head and yetprevent interference with the flow of the combustible material, there isprovided a rod holder 44 comprising two metallic elements 45 and 46suitably bent and welded or otherwise secured together in the mannershown in Fig. 3 to provide a hole 47 in which the rod 39 is removablyand free-fittedly supported. The rod holder may be provided with aplurality of recesses 48 into which the ring 42 is received. Thus, inthe exemplary embodiment disclosed in Figs. 1 to 3 the entire assemblycomprising the deflecting plate 38, the supporting rod 39, rod holder 44and ring 42 are operatively associated and suitably aflixed within theend portion of the tubular member 31. In some applications, it may bedesirable to support the entire assembly on the ring 42, as shown forexample, in Figs. 1 to 3, while in other applications a ledge may beprovided within the tubular member upon which the rod holder 44 may beplaced thereby supporting the entire assembly thereon.

It is notable that the instant burner head is versatile in itsapplication and provides numerous advantages in this direction. Forexample, attention is now directed to Figs. 4 and 5 wherein there isillustrated the instant burner head, designated in its entirety as 60,in an assembly the function of which is substantially similar to thathereinbefore described with respect to the structure disclosed in Figs.1 to 3. A review of the drawings will disclose that a different type oftubular member 55, deflecting device or plate 56 and support means 57therefor are employed while the particular type of Venturi shaped tube58 is similar in construction to the Venturi shaped tube 33 depicted inFigs. 1 to 3. In that portion of the tubular member with which thisinvention is primarily concerned, namely, the burner head 60, it isapparent that a ring 61 in the burner head is exactly the same ashereinbefore described with respect to the construction disclosed inFigs. 1 to 3 and is retained within the tubular member by dimples orprotuberances 62. For the purposes of manufacturing expediency thetubular member 55 may be provided with a flared end portion 63. It isnotable that in the construction of the burner head as illustrated inFigs. 4 and 5 there is no supporting means therewithin for thedeflecting plate. Thus, the deflecting plate 56, instead of beingaxially centrally supported within the burner head, is suitablysupported by a bracket or support means 58 which is so designed to bewelded or otherwise suitably affixed to the outside of the tubularmember as at 59 and designed to hold the deflecting device or plate at adesired angle with respect to the direction of the jet-like flow of gasand air from the burner head.

Thus, the burner assembly, when provided with the necessary mechanism(not shown in the interest of simplicity) for ejecting gas and primaryair in the Venturi shaped tube 58, will discharge a jet-like flow of thecombustible material against the deflecting plate 56.

Having thus described the particular structure of the new and improvedburner head of the single port type. for use primarily in gas typeburner assemblies, and to provide in general a working knowledge of theprinciples involved in its operation and use, reference is again made tothe drawings, particularly Figs. 1 and 2,

wherein there is shown a plurality of arrows diagrammaticallyrespectively representing the flow picture of the combustible materialconsonant with the operation of this burner.

For the purposes of illustration, let us consider that in the operationof the burner described, the gas and primary air as traveling in theduct 30 toward the discharge end thereof in the direction generallyindicated by arrows A located in that vicinity. This flow will beejected from the discharge end or port of the duct to form a jet-likeflow containing fuel either partially or fully mixed with primary air,the outer periphery or outer layer of which will have substantiallycomplete combustion because of the subsequent mixture of secondary air,the flow of which is generally indicated by arrows B in the furnace orchamber (not shown in the interest of simplicity). As is evident, thegreater portion of the jet will be largely uninfluenced until it reachesthe proximity of the deflecting plate 38 (the underside thereof as shownin Fig. 1) where it will be deflected outwardly thereby, as generallyindicated by the arrow C. Obviously, the deflecting plate 33 ultimatelycauses more secondary air to mix with the primary gas and air mixture sothat complete combustion is had beyond the deflecting plate, as clearlyindicated in Fig. 1, wherein the multiplicity of dashed lines indicatethe flaming or burning portions of said jet. Obviously, the principlesinvolved in the operation and use of the burner assembly indicated inFigs. 4 and 5 will be substantially similar with the exception that thejetlike flow is directed towards a deflecting plate 56 where it will bedeflected upwardly.

In order to make the burning jet operate efficiently, it is necessary(1) that secondary air be introduced into the flow of primary air andgas, and (2) that the velocity of the mixture of gas and primary air ora portion thereof must be slow enough so that combustion can take placewithin or near the port of the burner head. If these two steps are notfollowed either the jet will not burn at all, or if it does burn and thevelocity is not reduced there will be caused a phenomena known asblow-01f or lifting in which the flame will burn beyond the end of theburner head and which may cause it to be extinguished.

Thus, in the burner head of the type contemplated by this invention, theapplicant has judiciously placed a ring or impediment in the duct 30 sothat the mixture of primary air and gas is forced to contract andWithdraw from the surface of the duct or burner head, as clearlyillustrated in Fig. 2. On the side of the ring nearest the port, anegative pressure area or vacuum will result because of the lessening ofthe pressure caused by the ring reacting against the flow of themixture. This negative pressure is less than the pressure of the mixtureand less than the pressure of the ambient secondary air in the chamber.Thus, secondary air is caused to flow down the inside of the tubularmember or duct and to mix with an outer layer of the primary mixture asillustrated by flow arrows D. Obviously, the ring must be located orsuitably arranged so that the normal expansion of the mixtureintermediate the ring and the end portion of the tube will allow asuitable space for the secondary air to be admitted along the endportion of the burner head and thence to the negative pressure area.This travel of secondary air along the inner surface on the burner headtoward the negative pressure area being in the opposite direction willresult in the formation of a number of vortices and produce a somewhatturbulent area which will perform two functions to increase theefficiency of the burning jet. One of these functions will be themixture of the secondary air with the primary mixture of gas and air,and the other of these functions will be the reduction in the velocityof the outer periphery or layer of the primary mixture. This latterfunction has the advantage of maintaining the outer layer and themixture thereof with the secondary air at a slower velocity so that therate of combustion or rate of flame propagation will be at least asgreat as the velocity of the jet of primary mixture outward from theport. This will maintain the flame at or in the burner head thuspreventing the blow-oif or lifting phenomena previously mentioned.

Thus, by judiciously placing a ring within the burner head, a new andimproved type of burner has been accomplished which cooperates with theprimary mixture of air and gas to overcome all the prior objections ofthe previously cited attempts toward improvement in this type or".burner.

in adapting this burner head for use in a particular application,consideration should be given to the location and size of the ring inorder to provide the required negative pressure and availability of thesecondary air along the inner periphery of the tube.

The instant burner head being formed of simple parts and readilyavailable materials, lends itself to mass production manufacturingprinciples, thus affording a substantial savings in the manufacturingcosts.

From the foregoing disclosure, it may be observed that I have provided anew and improved burner head of the single port type which eflicientlyfulfills the objects and accomplishments as hereinbefore stated andprovides numerous advantages over prior type burner heads which isapparent to anyone skilled in the art.

While there is illustrated preferred embodiments of my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not Wish to be limited to the precise details ofconstruction set forth, but wish to avail myself of all changes withinthe scope of the appended claim.

I claim:

A gas burner head comprising an open ended duct having a flared portionthereon at its open end through which a jet of fuel is discharged andprovided with a plurality of inwardly extending proturberances spaced arelatively short distance from said flared portion, ring means having anexternal diameter substantially the same as the internal diameter ofsaid duct removably supported within said duct by said protuberances andin contact with said duct for a substantial portion of its periphery sothat when the ring means cooperates with the flow of the primary mixturea negative pressure is created between said flared portion and said ringmeans whereby secondary ambient air is caused to flow in a directionopposite to the flow of the primary mixture causing intermixing of thesecondary air in the primary mixture, support means disposed within saidopen ended duct radially inwardly of and supported by said ring means,said support means and said ring means forming a unitary assemblycapable of being removed from said duct as a unit, a deflecting platehaving a supporting rod, said support means including a pair ofangularly formed metallic members afflxed to each other and providing arecess receiving said deflecting plate supporting rod, and said membersfurther having recesses on their periphery receiving said ring means incircumscribed relation for supporting the assembly within the open endedduct.

References Cited in the file of this patent UNITED STATES PATENTS353,169 Shipman Nov. 23, 1886 1,434,256 Thompson Oct. 31, 1922 1,933,318Doen Oct. 31, 1933 2,368,370 Maxon Jan. 30, 1945 2,589,804 Harris Mar.18, 1952 2,600,709 Varley June 17, 1952 2,610,675 Downe Sept. 16, 1952

